Stainless Steel 309 (UNS S30900 / EN 1.4828)

Stainless Steel 309 (UNS S30900 / EN 1.4828) – Specifications, Properties and Applications

Stainless Steel 309 (UNS S30900 / EN 1.4828) is a heat-resistant austenitic stainless steel with a higher chromium and nickel content than Stainless Steel 304. It is specifically designed for applications requiring superior oxidation resistance and excellent mechanical performance at elevated temperatures.

Grade 309 offers outstanding resistance to scaling, thermal shock, and oxidation, making it ideal for industrial furnaces, heat treatment equipment, petrochemical plants, power generation facilities, and high-temperature process industries. In addition to its excellent heat resistance, Stainless Steel 309 provides good corrosion resistance in moderately corrosive environments and excellent fabrication characteristics.

Emirerri Steel supplies Stainless Steel 309 in sheets, plates, coils, pipes, tubes, round bars, flanges, and pipe fittings to customers across Tunisia, Algeria, Morocco, Libya, and international markets.

Key Features of Stainless Steel 309

  • Excellent high-temperature oxidation resistance
  • Superior heat resistance
  • High chromium and nickel content
  • Good corrosion resistance
  • Excellent creep resistance
  • Outstanding weldability
  • Good formability
  • Excellent thermal shock resistance
  • Long service life
  • Low maintenance requirements

Stainless Steel 309 Specifications

SpecificationDetails
GradeStainless Steel 309
UNS NumberS30900
Werkstoff Number1.4828
EN DesignationX15CrNiSi20-12
Stainless Steel FamilyAustenitic Stainless Steel
StandardsASTM A240, ASTM A276, ASTM A312, ASTM A182, EN 10088
Product FormsSheet, Plate, Coil, Pipe, Tube, Round Bar, Flanges, Pipe Fittings
Surface FinishNo.1, 2B, BA, No.4, Mirror Finish
Supply ConditionSolution Annealed

Equivalent Grades of Stainless Steel 309

StandardEquivalent Grade
ASTM309
UNSS30900
EN1.4828
DINX15CrNiSi20-12
JISSUS309
ISOX15CrNiSi20-12

Available Sizes

Plates
  • Thickness: 5 mm to 100 mm
  • Width: 1000 mm to 2500 mm
  • Length: Up to 12000 mm
Sheets
  • Thickness: 0.5 mm to 6 mm
  • Width: Up to 2000 mm
Pipes & Tubes
  • Outside Diameter: 6 mm to 610 mm
  • Wall Thickness: 0.5 mm to 40 mm
Round Bars
  • Diameter: 6 mm to 500 mm

Chemical Composition of Stainless Steel 309

ElementComposition (%)
Chromium (Cr)22.0 – 24.0
Nickel (Ni)12.0 – 15.0
Carbon (C)≤ 0.20
Manganese (Mn)≤ 2.00
Silicon (Si)≤ 1.50
Phosphorus (P)≤ 0.045
Sulfur (S)≤ 0.030
Iron (Fe)Balance

Mechanical Properties of Stainless Steel 309

PropertyValue
Tensile Strength≥ 515 MPa
Yield Strength (0.2% Offset)≥ 205 MPa
Elongation≥ 40%
Hardness≤ 217 HB
Modulus of Elasticity193 GPa

Physical Properties of Stainless Steel 309

PropertyValue
Density7.90 g/cm³
Melting Range1398 – 1454°C
Thermal Conductivity14.2 W/m·K
Electrical Resistivity0.78 µΩ·m
Specific Heat Capacity500 J/kg·K
Magnetic PermeabilityEssentially Non-Magnetic (Annealed Condition)

Types of Stainless Steel 309 Products

Stainless Steel 309 Plates

Designed for industrial furnaces, boilers, and high-temperature pressure vessels.

Stainless Steel 309 Sheets

Suitable for furnace linings, heat shields, and industrial fabrication.

Stainless Steel 309 Pipes

Used in petrochemical plants, refineries, and high-temperature process piping.

Stainless Steel 309 Tubes

Ideal for heat exchangers, superheaters, and thermal processing equipment.

Stainless Steel 309 Round Bars

Used in shafts, furnace fixtures, fasteners, and machined components.

Stainless Steel 309 Flanges & Pipe Fittings

Manufactured for high-temperature piping systems in power generation and chemical processing industries.

Corrosion Resistance

Stainless Steel 309 provides excellent resistance to:

  • Atmospheric corrosion
  • High-temperature oxidation
  • Oxidizing gases
  • Organic acids
  • Industrial atmospheres
  • Scaling at elevated temperatures

Although Grade 309 has good corrosion resistance, it is primarily designed for heat-resistant service rather than severe chloride environments. For marine or highly saline applications, Stainless Steel 316 or 316L is generally recommended.

Heat Resistance

Stainless Steel 309 is specifically engineered for continuous exposure to elevated temperatures.

Service Temperature
  • Continuous Service: Up to approximately 1000°C
  • Intermittent Service: Up to approximately 1035°C
Benefits
  • Outstanding oxidation resistance
  • Excellent scaling resistance
  • Superior creep strength
  • Good thermal shock resistance
  • Stable mechanical properties at elevated temperatures

Traitement Thermique

Recuit de Mise en Solution
  • Température : 1035°C à 1120°C
  • Refroidissement rapide à l’eau ou à l’air
Avantages
  • Restauration des propriétés mécaniques
  • Amélioration de la résistance à la corrosion
  • Réduction des contraintes internes

Le 309 ne peut pas être durci par traitement thermique, mais il peut être renforcé par écrouissage.

Welding of Stainless Steel 309

Grade 309 offers excellent weldability using standard welding processes.

Recommended Welding Methods

  • GTAW (TIG)
  • GMAW (MIG)
  • SMAW (Shielded Metal Arc Welding)
  • SAW (Submerged Arc Welding)
  • Resistance Welding

Welding Advantages

  • Excellent weld integrity
  • No preheating normally required
  • Good resistance to hot cracking
  • Reliable performance in high-temperature service

Post-weld cleaning, pickling, and passivation are recommended to restore optimum corrosion resistance.

Fabrication of Stainless Steel 309

Machining
  • Turning
  • Milling
  • Drilling
  • Threading
Forming
  • Cold bending
  • Roll forming
  • Press forming
  • Deep drawing
Cutting
  • Laser cutting
  • Plasma cutting
  • Waterjet cutting
  • Mechanical sawing
Surface Finishing
  • Pickling
  • Passivation
  • Mechanical polishing
  • Electropolishing

Applications of Stainless Steel 309

Furnace Industry
  • Furnace linings
  • Burner components
  • Furnace conveyors
  • Heat treatment baskets
Petrochemical Industry
  • Reactors
  • Process piping
  • Heat exchangers
  • Refinery equipment
Power Generation
  • Boilers
  • Superheaters
  • Steam piping
  • Thermal recovery systems
Chemical Processing
  • High-temperature vessels
  • Industrial tanks
  • Processing equipment
Thermal Processing Industry
  • Annealing furnaces
  • Kilns
  • Combustion chambers
  • Incinerator components
Industrial Manufacturing
  • High-temperature machinery
  • Exhaust systems
  • Heat-resistant structural components

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